128  
FXUS65 KBYZ 160807  
AFDBYZ  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BILLINGS MT  
207 AM MDT THU OCT 16 2025  
   
KEY MESSAGES
 
 
 
- LOWER ELEVATION RAIN AND MOUNTAIN SNOW THROUGH EVENING;  
HEAVIEST PRECIPITATION EAST OF BILLINGS; SNOW LEVELS FALL TO  
AROUND 7000 FEET.  
 
- BRISK WIND AND A LITTLE WARMER FRIDAY; THEN SCATTERED SHOWERS  
LIKELY FRIDAY NIGHT THROUGH SATURDAY MORNING.  
 
- DRY AND WARMER SUNDAY (TEMPS IN 60S TO NEAR 70F).  
 
- TURNING COOLER WITH CHANCE OF PRECIPITATION AGAIN MONDAY;  
FOLLOWED BY DRIER CONDITIONS AND SEASONABLE TEMPS TUESDAY AND  
WEDNESDAY.  
 

 
   
DISCUSSION
 
 
TODAY THROUGH TONIGHT (THURSDAY)...  
 
SATELLITE IMAGERY SHOWED AN UPPER LOW SPINNING OVER UTAH PUSHING  
TOWARD SOUTHWEST WY WHILE A DEFORMATION ZONE AND DIFFLUENT UPPER  
FLOW WERE SHIFTING EAST ACROSS SOUTHERN MT AND NORTHERN WY. ENHANCED  
CLOUD TOPS WERE INDICATED IN THESE AREAS AS WELL AS SE  
MT...EVIDENCE OF STRONG ASCENT ASSOCIATED WITH THE SYSTEM.  
 
AS THE UPPER LOW TRACKS NORTHEAST ACROSS WY TODAY WE WILL SEE  
FAVORABLE DYNAMICS FOR ASCENT PERSIST OVER OUR FORECAST AREA,  
WHILE MOIST NORTHERLY FLOW DEVELOPS IN THE LOW-MID LEVELS. AREAS  
OF SHOWERS SHOULD BE EXPECTED, POSSIBLY HEAVY, ESPECIALLY ACROSS  
THE EASTERN SECTIONS (ROSEBUD COUNTY EASTWARD INTO FALLON COUNTY).  
THE PROBABILITY OF 0.50 INCHES OF PRECIPITATION THROUGH THIS  
EVENING RANGES FROM 15% OVER PARK COUNTY TO 85% AT MILES CITY AND  
BAKER. IN THE MEANTIME SNOW LEVELS WILL DROP TO AROUND 7K FT  
THROUGH THE DAY WITH 4-8 INCHES OF ADDITIONAL ACCUMULATION  
POSSIBLE FROM NOW THROUGH THIS EVENING. GREATEST ACCUMULATIONS  
WIL BE ABOVE 8K FT ON NORTH/NORTHWEST FACING SLOPES, WITH ONLY  
LIGHT ACCUMULATIONS EXPECTED IN THE COOKE CITY VICINITY. THE BIG  
HORN MTNS SHOULD SEE ONLY 1-4 INCHES OF ACCUMULATION OVER HIGHER  
ELEVATIONS. TEMPS TODAY WILL REMAIN BELOW SEASONAL AVERAGES WITH  
READINGS IN THE MID TO UPPER 40S COMMON. LOOK FOR BRISK NORTHWEST  
WIND TO 10-20 MPH TO MAKE IT FEEL A LITTLE COOLER.  
 
THE UPPER LOW IS PROGGED TO BE OVER SE MT BY EVENING, AND HEADING  
INTO THE HIGH PLAINS OF THE DAKOTAS. CROSS SECTIONS SHOW MUCH  
DRIER AIR QUICKLY MOVING INTO OUR WESTERN AREAS AS THE UPPER LOW  
EXITS TO THE EAST. SO LOOK FOR DECREASING PRECIPITATION FROM WEST  
TO EAST DURING THE EVENING. TOUGH OUTDOOR CONDITIONS WILL LINGER  
THOUGH IN OUR FAR EAST WITH POCKETS/BANDS OF RAIN AND WESTERLY  
WINDS 20-35 MPH WITHIN A TROWAL THAT DEVELOPS OVER THE EAST  
CENTRAL ZONES (FALLON AREA) IN THE EVENING. RAINFALL SHOULD BE  
ABOUT DONE AFTER MIDNIGHT AND WINDS DECREASE BEFORE SUNRISE  
FRIDAY.  
 
FRIDAY AND SATURDAY...LOOK FOR A PERIOD OF SUBSIDENCE AND DRYING,  
WITH GUSTY WEST WINDS ON FRIDAY. ENSEMBLES SUGGEST THE  
PROBABILITY OF GUSTS EXCEEDING 40 MPH IS 40-70% FOR MOST AREAS,  
BUT AS HIGH AS 90% FOR OUR WESTERN FOOTHILLS THANKS TO A DECENT  
PRESSURE GRADIENT AND 700MB WINDS 30-40 KTS. CANNOT RULE OUT GUSTS  
TO 50 MPH AT HARLOWTON, BIG TIMBER OR LIVINGSTON. HIGHS ON FRIDAY  
WILL BE IN THE MID 50S TO LOWER 60S.  
 
A FAST-MOVING SHORTWAVE IN WNW FLOW ALOFT WILL PUSH ACROSS THE  
AREA FRIDAY NIGHT THROUGH MIDDAY SATURDAY. THIS FEATURE WILL  
BRING MORE SHOWERS TO LOWER ELEVATIONS FRIDAY EVENING THROUGH  
SATURDAY MORNING ALONG WITH A FEW INCHES OF MOUNTAIN SNOW,  
FOLLOWED BY ANOTHER DOSE OF BREEZY W-NW WINDS. HIGHS ON SATURDAY  
WILL BE A LITTLE COOLER THAN FRIDAY, MAINLY IN THE 50S.  
 
SUNDAY...  
THIS IS A DRY AND WARMER DAY UNDER A BRIEF PERIOD OF SHORTWAVE  
RIDGING. LOOK FOR HIGHS IN THE 60S. THERE REMAINS A SIGN OF SOME  
ENHANCED GAP FLOW SATURDAY NIGHT INTO EARLY SUNDAY, AND PERHAPS  
40-50 MPH GUSTS AT LIVINGSTON AND NYE (50% CHANCE).  
 
MONDAY THROUGH NEXT WEDNESDAY...  
CLUSTER ANALYSIS INDICATES BETTER AGREEMENT THAT A BROAD LOW  
AMPLITUDE TROUGH WILL PUSH ACROSS MONTANA SUNDAY NIGHT THROUGH  
MONDAY BRINGING ANOTHER SHOT OF RAIN SHOWERS AND MOUNTAIN SNOW.  
THIS LOOKS TO BE FOLLOWED BY MODEST RIDGING OR WESTERLY ZONAL FLOW  
TUESDAY AND WEDNESDAY WITH SEASONAL TEMPS AND MAINLY DRY  
CONDITIONS. BT  
   
AVIATION
 
 
WIDESPREAD SHOWERS WILL CONTINUE TO IMPACT EASTERN MT AND  
NORTHERN WY, GRADUALLY EXPANDING WEST TOWARDS KBIL THROUGH THE  
MORNING. LOW STRATUS/FOG WILL CONTINUE THROUGH THIS EVENING,  
SLOWLY DISSIPATING AS THE SYSTEM MOVES EAST. MVFR/IFR CONDITIONS  
WILL BE COMMON WITH IFR/LIFR POSSIBLE UNDER HEAVY RAIN AND VERY  
LOW CEILINGS. MOUNTAIN OBSCURATIONS CAN BE EXPECTED THROUGH THE  
PERIOD. TS  
 

 
   
PRELIMINARY POINT TEMP/POPS
 
 
TDY FRI SAT SUN MON TUE WED  
-------------------------------------------------------  
BIL 048 040/063 037/056 039/066 041/052 034/054 035/058  
9/W 30/U 40/U 01/B 54/W 11/B 10/B  
LVM 048 032/060 028/054 034/064 030/048 026/052 029/055  
7/W 10/N 50/U 04/W 75/W 11/B 11/B  
HDN 047 037/062 035/055 033/066 038/054 031/055 032/058  
+/W 70/U 61/U 01/B 64/W 21/B 10/B  
MLS 050 040/059 035/053 034/066 040/054 032/054 034/058  
+/W 90/N 30/U 00/B 32/W 10/U 10/B  
4BQ 048 041/058 036/051 034/067 041/054 032/053 034/055  
+/W 80/U 40/U 00/U 32/W 11/U 10/U  
BHK 051 037/060 032/053 029/066 036/055 029/053 030/057  
+/W 91/N 20/N 00/U 21/N 10/U 10/U  
SHR 046 032/061 030/052 029/068 034/052 026/053 029/055  
+/W 60/U 61/B 00/U 55/W 21/U 10/U  
 

 
   
BYZ WATCHES/WARNINGS/ADVISORIES
 
 
MT...NONE.  
WY...NONE.  
 

 
 

 
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